1. Field
Example embodiments relate to a separation membrane, a method of manufacturing the same, and a water treatment device including the same.
2. Description of the Related Art
There has been growing interest in forward osmosis (FO) technology with an increasing demand for the development of a separation membrane having a higher efficiency but lower energy consumption.
Forward osmosis, like reverse osmosis, requires a semi-permeable membrane that is capable of filtering an osmotic pressure-drawing solute. However, forward osmosis uses a concentration difference instead of a pressure difference in order to separate materials, unlike reverse osmosis. Thus, a forward osmosis process may be operated under a relatively low pressure or even without any pressure.
On the contrary, a reverse osmosis process is operated by using a separation membrane (e.g., for filtering salt or foreign particles) that is laminated on a support layer that can endure a relatively high pressure, since water is separated from the unwanted substances with pressure. However, since the forward osmosis process separates unwanted substances from water using diffusion according to an osmotic pressure (rather than by directly applying pressure), a support layer may have hydrophilicity as well as porosity or tortuosity, thickness, and the like, so that the support layer may help with the water diffusion. A more hydrophilic, thinner, and more porous support layer has been reported to improve permeability of a separation membrane.